Author	Marheinecke, U.
Year	1992
Journal	Palaeontographica, Abt.B, vol.227
Title	Monographie der Dinozysten, Acritarcha und Chlorophyta des Maastrichtium von Hemmoor (Niedersachsen).

Abstract Marheinecke, U., 1992: Monographie der Dinozysten, Acritarcha und Chlorophyta des Maastrichtium von Hemmoor (Niedersachsen). Palaeontographica, Abt.B, vol.227 Abstract A well preserved and rich assemblage of fossil organic-walled microphytoplankton, from the Maastrichtian standard-section of Hemmoor (Niedersachsen, Germany), is described. It comprises: 164 species and subspecies of dinocysts, 7 acritarch species and 4 species of chlorophyta. New taxa described are the genera Neonorthidium n. g. (dinocyst) and Multicorisphaeridium n. g. (acritarch) and 30 infrageneric taxa. Emended diagnosis and/or new combinations are presented for 12 taxa. Several new terms are introduced to describe the construction of processes and septa in the Spiniferites-complex. The borderlines between the main genera are discussed. For the first time it is possible to determine the areation of Achomosphaera ramulifera from form and placement of the processes. The Maastrichtian of Hemmoor is divided into 4 dinocyst-zones with 9 sub-zones. Correlations are made between this zonation and all known dinocyst-zonations of the boreal uppermost Cretaceous. Using the SIMPSON-index the similarity between the Hemmoor section and 35 other European and non-European palynofloras is demonstrated. These similarities can be correlated and indicate well defined dinocyst-provinces and reflect ocean currents in the uppermost Cretaceous. Furthermore there is a sharp maximum of similarity occuring in Campanian to Danian strata.